Analysing the city as a system in constant transformation, it’s possible to identify a multiplicity of spaces in
different stages of evolution, in each moment it´s possible to group them in two main types of spaces. Some
are relatively consolidated spaces that enclose, presumably in the long term, a purpose, a spatial
configuration and a legible identity, normally they are recognized in a certain sociocultural context and
predominate in the city. The other spaces are those where the purpose, the structure or the identity is
unclear, in a certain moment of its Landscape. This second type of spaces, denominated in this study as
“Espaços em Aberto”, are experienced through a pedestrian path and, simultaneously, analyzed in its
temporal and spatial circumstances in order to discover the limitations, but specially the potentials and
opportunities that these spaces contain. In order to intervene in this type of spaces besides the study of the
character and the situation is necessary to understand the differences and the economic and social energy
available to do it. The participatory approach is develop as a form of activation and rehabilitation of the
Espaços em Aberto. Therefore different concepts of participation, spatialization and the several cases of
intervention in urban public spaces are studied. Were designed and implemented four strategies of
intervention in four spaces with different contexts